Payback is the number every owner asks for and every salesman inflates. Here are the figures we use in our own financial model, with the assumptions written down so you can argue with them.
Key facts
- A 30–35 kWp solar system replacing a diesel generator on an oil press in Ibadan pays back in 3–4 years.
- A full site — solar, battery and 10–50 MT cold storage, about US$564,000 of equipment — pays back in about 4.5 years with an unlevered return of 17.3%.
- Under Energy-as-a-Service the customer's payback is immediate: no capital outlay, fee 20–30% below today's spend.
- Batteries are the swing factor: a 15,000-cycle graphene LFP battery lasts the contract; a cheap battery may need replacing twice.
Small site, direct purchase
A 15 kW three-phase oil press running eight hours a day needs about 120 kWh a day. On diesel that is roughly ₦12 million a year in fuel plus a ₦2 million generator. The solar plus battery system that replaces it costs US$26,000–42,000 landed and installed, so the fuel saving alone repays it in three to four years — and the press runs its full shift on sunshine.
Full site, financed
Our standard Phase 1 site costs about US$564,000 in equipment and earns US$144,000 a year in service fees against US$23,000 of operations and maintenance. Net operating income is about US$121,000 a year — an 84% margin — which gives a 4.5-year payback and a 17.3% unlevered return over an 8-year contract. Those are the numbers development finance institutions have reviewed.
What shortens or lengthens payback
- Diesel price and hours of generator use — the higher, the faster
- Battery size: over-sizing for full overnight autonomy roughly doubles battery cost and pushes payback past the contract length
- Grid availability: a few hours of grid a day lets the battery be smaller
- Freight distance and customs duties
- Whether the site earns dollars (standard terms) or local currency (protections add cost)
Get the payback for your site in writing.
Talk to Frontières BayFrequently asked
Why not size the battery to run everything overnight?
Because it costs almost as much as the rest of the site and takes payback from 4.5 to 9–10 years. Pre-cooling and thermal mass carry most of the night; the battery covers the rest.
Does payback include maintenance?
Yes — US$23,000 a year of operations and maintenance is in the model.